Name: _____________________________________________ Date: _______________ Period: __________
4.3: Water, Air, & Land Resources
I. The Water Planet
 Water covers nearly 71% of Earth’s surface.
◦ Mostly saltwater; less than 1% is USABLE fresh water
◦ Ocean currents help control Earth’s climate
◦ Freshwater is vital to life

Two types of water pollution
◦ Point source pollution: from a known & specific location, such as factory pipes
◦ Nonpoint source pollution: does not have a specific point of origin, such as runoff (water that flows
over land rather than seeping into the ground)
II. Earth’s Blanket of Air
 The chemical composition of the atmosphere helps maintain life on Earth.
◦ Nitrogen, oxygen, water vapor, and other gases
 The oxygen is vital to life, but the atmosphere has other functions:
◦ Part of earth cycles such as the carbon cycle
◦ Shields us from 95% of the sun’s UV radiation
◦ Helps maintain a warm temperature near the surface
 Air pollution changes the chemical composition of the atmosphere, disrupting natural cycles and
functions.
◦ Major source of air pollution is the combustion of fossil fuels.
◦
◦

Form smog & acid rain
The increased amount of carbon dioxide in the atmosphere since the industrial revolution has
contributed to the unnatural heating of the lower atmosphere, called global warming.

Could lead to the melting of glaciers, which would cause a catastrophic rise in sea level
Chlorofluorocarbons (CFCs) once used in air conditioners and plastic, destroy ozone.

◦
A significant loss of ozone could lead to increased health problems because of the increased UV
radiation.
Air pollution is also a public health concern: asthma; irritation of the lungs, eyes, and throat;
bronchitis; emphysema; and lung cancer.
III. Land Resources
 Earth’s land provides soil and forests, as well as mineral and energy resources.
◦ Soil—food; forest—lumber for buildings, wood for furniture, pulp for paper; petroleum—energy and
plastics; minerals & metals—coins, machines, building materials
 Damage comes from several sources:
◦ Mining tears the surface, destroys vegetation, causes soil erosion, and creates pollution that
contaminates surrounding soil and water.
◦ Agriculture results in depletion of groundwater and the build-up of salts in soil from irrigation.
◦ Clear-cutting trees causes soil erosion.
 Land also serves as a disposal site.
4.4 Protecting Resources
I. Conservation
 Conservation is careful use of resources.
◦ Each year, Americans throw away:






30 million cell phones
18 million computers
8 million TVs
Enough tires to circle the world 3 times
Do not confuse conservation with pollution prevention, which stops pollution from entering the
environment.
Between 1940 and 1970, several serious pollution problems caught our attention:
◦ Beaches in the 1960s closed due to pollution
◦ Oil spill off California coast in 1969 killing wildlife
◦ In 1969, Ohio’s Cuyahoga River caught fire and burned for days because of all the pollution present.
II. Keeping Water Clean & Safe
 Starting in the 1970s, the federal government passed several laws to prevent or decrease pollution and
protect resources.
 The Clean Water Act of 1972 required industries to reduce or eliminate point source pollution into surface
waters & increased the number of sewage treatment plants.
◦ Safe swimming & fishing water increased from 36% to 62% between 1972 and the end of the 1990s.
 The Safe Drinking Water Act of 1974 set maximum contaminant levels for several pollutants that can
harm the health of people.
III. Protecting the Air
 In 1970, Congress passed the Clean Air Act, the nation’s most important air pollution law.
◦ Established permissible levels of six major pollutants known to cause health problems: carbon
monoxide, ozone, lead, sulfur dioxide, nitrogen oxides, and fine particulates.
◦ If maximum levels are exceed, local authorities must come up with a plan to bring them down.
 Today’s power plants and motor vehicles use pollution control devices to cut down on pollutants released
from fossil fuel combustion.
◦ By reducing our consumption of electricity, we can further reduce the amount of air pollution.
IV. Caring for Land Resources
 Protecting land resources involves preventing pollution and managing land resources wisely.
◦ Farmers now use many soil conservation practices to prevent loss of topsoil and preserve soil fertility
such as contour plowing and strip cropping.
◦ Selective cutting conserves forest resources.
◦ Fewer pesticides and inorganic fertilizers decrease chemicals in the soil; the use of compost and
integrated pest management come first.


The Resource Conservation and Recovery Act of 1976 has decreased the illegal and unsafe dumping of
hazardous wastes.
The 1980 Comprehensive Environmental Response, Compensation, and Liability Act mandates the
cleaning up of abandoned hazardous waste sites that are a danger to the public or the environment.

Creating less waste by using fewer products and recycling products also helps preserve land resources.